Interferon alfa-2b XL (IFN alfa-2b XL) is a novel sustained release interferon α-2b drug product that is being developed by FLAMEL TECHNOLOGIES using its Medusa® technology, aiming at reducing the toxicity and enhancing the biological response. In the present study, patients will be randomly assigned to either IFN alfa-2b XL 27 MUI, IFN alfa-2b XL 36 MUI, or IFN peg alfa-2b 1.5 µg/kg, all administered once a week for 12 weeks by subcutaneous injections, in combination with weight dosed ribavirin daily administered orally in two divided doses. Doses will be adapted according to the dose modification guidelines for combination therapy labelled in the ribavirin prescribing information.